1. Field of the Invention
The present invention relates to a print head composed of a liquid ejecting head that ejects desired droplets utilizing bubbles generated by applying thermal energy to a liquid.
2. Description of the Related Art
Some printing apparatuses function as a printer, a copier, a facsimile, or the like, and some printing apparatuses are used as output instruments for composite electric instruments or workstations including computers and word processors. Among these printing apparatuses, ink jet printing apparatuses have been prevailing which carry out printing by ejecting ink to print media such as paper, clothes, plastic sheets, or OHP sheets on the basis of print information.
In particular, industrial ink jet printing apparatuses use a variety of print media, and various demands are being made for the material of the print media. In recent years, much effort has been made to meet these demands. Printing apparatuses have also been used which use clothes, leathers, non-woven fabrics, or metal as print media, in place of normal print media such as paper or thin resin sheets. The ink jet printing apparatus makes reduced noise, requires reduced running costs, and can be easily configured for color printing. Consequently, the ink jet printing apparatus is now widely applied to printers, copiers, facsimile machines, and the like.
Known ink jet print heads used for ink jet printing apparatuses use various schemes to form ejecting ink droplets. In particular, an ink jet print head utilizing heat as energy to eject ink can be provided with a high-density multinozzle to achieve high-resolution, high-quality, and fast printing.
With this scheme, print elements are provided in ink channels that are in communication with the respective ink ejection opening in the ink jet print head. Electric energy or power corresponding to a print signal is selectively applied to these print elements. Thermal energy generated by the application of electric energy is used to rapidly heat ink on a heat acting surface to cause film boiling. The pressure of bubbles resulting from the film boiling ejects ink from the ink ejection openings.
FIG. 17 is a perspective view schematically showing the configuration of a conventional ink jet print head. A known method for manufacturing this liquid ejecting head, for example, forms fine grooves 1202 in a plate 1203 such as glass or metal by machining means such as cutting or etching and then joins the plate 1203 in which the grooves 1202 have been formed to a roof plate 1201 to form liquid channels. Ejection openings in the head may be formed by attaching a plate called an orifice plate in which the ejection openings are formed.